xenserver/etc_xapi.d_plugins_openvswitch-cfg-update

   1 #!/usr/bin/env python
   2 #
   3 # xapi plugin script to update the cache of configuration items in the
   4 # ovs-vswitchd configuration that are managed in the xapi database when
   5 # integrated with Citrix management tools.
   6
   7 # Copyright (C) 2009, 2010 Nicira Networks, Inc.
   8 #
   9 # Licensed under the Apache License, Version 2.0 (the "License");
  10 # you may not use this file except in compliance with the License.
  11 # You may obtain a copy of the License at:
  12 #
  13 #     http://www.apache.org/licenses/LICENSE-2.0
  14 #
  15 # Unless required by applicable law or agreed to in writing, software
  16 # distributed under the License is distributed on an "AS IS" BASIS,
  17 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  18 # See the License for the specific language governing permissions and
  19 # limitations under the License.
  20
  21 # TBD: - error handling needs to be improved.  Currently this can leave
  22 # TBD:   the system in a bad state if anything goes wrong.
  23
  24 import XenAPIPlugin
  25 import XenAPI
  26 import os
  27 import subprocess
  28 import syslog
  29
  30 vsctl="/usr/bin/ovs-vsctl"
  31 cacert_filename="/etc/openvswitch/vswitchd.cacert"
  32
  33 # Delete the CA certificate, so that we go back to boot-strapping mode
  34 def delete_cacert():
  35     try:
  36         os.remove(cacert_filename)
  37     except OSError:
  38         # Ignore error if file doesn't exist
  39         pass
  40
  41 def update(session, args):
  42     pools = session.xenapi.pool.get_all()
  43     # We assume there is only ever one pool...
  44     if len(pools) == 0:
  45         raise XenAPIPlugin.Failure("NO_POOL_FOR_HOST", [])
  46     if len(pools) > 1:
  47         raise XenAPIPlugin.Failure("MORE_THAN_ONE_POOL_FOR_HOST", [])
  48     pool = session.xenapi.pool.get_record(pools[0])
  49     try:
  50         try:
  51             controller = pool["vswitch_controller"]
  52         except KeyError:
  53             # On systems older than XenServer 5.6.0, we needed to store
  54             # the key in "other_config".
  55             controller = pool["other_config"]["vSwitchController"]
  56     except KeyError, e:
  57         controller = ""
  58     currentController = vswitchCurrentController()
  59     if controller == "" and currentController != "":
  60         delete_cacert()
  61         try:
  62             emergency_reset(session, None)
  63         except:
  64             pass
  65         removeControllerCfg()
  66         return "Successfully removed controller config"
  67     elif controller != currentController:
  68         delete_cacert()
  69         try:
  70             emergency_reset(session, None)
  71         except:
  72             pass
  73         setControllerCfg(controller)
  74         return "Successfully set controller to " + controller
  75     else:
  76         return "No change to configuration"
  77
  78 def vswitchCurrentController():
  79     controller = vswitchCfgQuery(["get", "Open_vSwitch",
  80                                   ".", "managers"]).strip('[]"')
  81     if controller == "":
  82         return controller
  83     if len(controller) < 4 or controller[0:4] != "ssl:":
  84         return controller
  85     else:
  86         return controller.split(':')[1]
  87
  88 def removeControllerCfg():
  89     vswitchCfgMod(["--", "clear", "Open_vSwitch", ".", "managers",
  90                    "--", "del-ssl"])
  91
  92 def setControllerCfg(controller):
  93     # /etc/xensource/xapi-ssl.pem is mentioned twice below because it
  94     # contains both the private key and the certificate.
  95     vswitchCfgMod(["--", "clear", "Open_vSwitch", ".", "managers",
  96                    "--", "del-ssl",
  97                    "--", "--bootstrap", "set-ssl",
  98                    "/etc/xensource/xapi-ssl.pem",
  99                    "/etc/xensource/xapi-ssl.pem",
 100                    cacert_filename,
 101                    "--", "set", "Open_vSwitch", ".",
 102                    'managers="ssl:' + controller + ':6632"'])
 103
 104 def vswitchCfgQuery(action_args):
 105     cmd = [vsctl, "-vANY:console:emer"] + action_args
 106     output = subprocess.Popen(cmd, stdout=subprocess.PIPE).communicate()
 107     if len(output) == 0 or output[0] == None:
 108         output = ""
 109     else:
 110         output = output[0].strip()
 111     return output
 112
 113 def vswitchCfgMod(action_args):
 114     cmd = [vsctl, "-vANY:console:emer"] + action_args
 115     exitcode = subprocess.call(cmd)
 116     if exitcode != 0:
 117         raise XenAPIPlugin.Failure("VSWITCH_CONFIG_MOD_FAILURE",
 118                                    [ str(exitcode) , str(action_args) ])
 119
 120 def emergency_reset(session, args):
 121     cmd = [vsctl, "emer-reset"]
 122     exitcode = subprocess.call(cmd)
 123     if exitcode != 0:
 124         raise XenAPIPlugin.Failure("VSWITCH_EMER_RESET_FAILURE",
 125                                    [ str(exitcode) ])
 126
 127     return "Successfully reset configuration"
 128
 129 if __name__ == "__main__":
 130     XenAPIPlugin.dispatch({"update": update,
 131                            "emergency_reset": emergency_reset})